blazuki
How about a spirit version of 9 tails from naruto. It can be a spirit of yin and yang energy or chi itself. It will give the mc a large stat in chi and maybe use the naruto world logic to change the nature of chi to create other elements (maybe make it so that the mc will use more chi when bending other elements).
Good chap. So my understanding is that leveling up never increases his chi and only his control, thus never increasing his power? I could've sworn his chi increased before. But anyway, fusing with a spirit is not a bad idea, good powerup, and maybe Chen would become more interesting if he has his own Kurama. But then again he might stop training completely and just laze around if he gets a massive powerup.